On man, 2004-11-29 at 18:19 +0000, Tony Finch wrote:
We're using the CMU Cyrus Sieve implementation. A few of our more advanced
users have asked how to identify bounce messages in a Sieve script. The
obvious doesn't work:
if envelope :is "from" ""
seems like a bug to me.
The best phrasing we have seen is
if not envelope :contains "from" "@"
which is a rather ugly circumlocution. RFC 3028 doesn't say anything about
null return paths, which is clearly an omission. As a result the Cyrus
behaviour is hard to classify as a bug.
I don't see why RFC 3028 needs to mention that case explicitly.
If one of the envelope-part strings is (case insensitive) "from",
then matching occurs against the FROM address used in the SMTP MAIL
command.
ok, perhaps it should be a bit more careful in use of terminology and
say "reverse-path address" instead of "FROM address" (to remove all
doubt about what happens to extra parameters on MAIL FROM). it also
would be nice if it was explicit about what to do with the surrounding
brackets, even though formally, the brackets are not part of
reverse-path.
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